Hi,
On 2026-01-29 12:50:38 -0500, Peter Geoghegan wrote:
> On Thu, Jan 29, 2026 at 12:42 PM Andres Freund <andres@anarazel.de> wrote:
> > > - /*
> > > - * We better not already hold a lock on the buffer.
> > > - */
> > > Assert(entry->data.lockmode == BUFFER_LOCK_UNLOCK);
> > >
> >
> > Err, this should have been removed, I accidentally re-added the hunk while
> > experimenting.
>
> I've been running into this assertion failure from time to time while
> working on index prefetching. It seems to happen after a hard crash.
> I've just been running initdb whenever it happens. It would be nice to
> not have to do this again.
Sure, I'm planning to give folks a bit longer to chime in whether the proposed
behavior is sane and will then push (with an amended commit message and the
fixup discussed here).
After a crash it seems that btree often ends up getting the page from FSM that
it's currently inserting on. Which makes some sense, because presumably that
was the page we filled just before a crash. Wonder if - independent of this
issue - it could make sense to update the FSM during nbtree WAL recovery...
Greetings,
Andres Freund
